Species 6 (1 in the flora): temperate regions, North America, Eurasia.

Clematis subg. Viticella has sometimes been included in Clematis subg. Viorna , as suggested by F. B. Essig (1992), although it is very different from subg. Viorna in the strict sense in the aspect of its flowers and was treated as a distinct genus by earlier authors.

Several other large-flowered European and Asiatic species and hybrids, including Clematis campaniflora Brotero, with broadly campanulate perianth, and C. florida Thunberg, C. lanuginosa Lindley, and C . × jackmanii T. Moore (= C. lanuginosa × C. viticella ), with rotate perianth often with 6-8 sepals, occasionally persist after cultivation; in some cases they have become very locally naturalized.